Method and device for regulating a wind machine

ABSTRACT

A method and corresponding apparatus for regulating a system that produces electric power, the system including an electric alternator having a rotor integral with a rotating part of a wind machine to form a rotary assembly, and a power electronics module, the method including the steps of: producing an alternating current at output terminals of the alternator; converting the alternating current produced by the alternator into modulated pulses of direct current. Alternating electric current produced by the alternator is regulated by controlling the speed of rotation of the rotary assembly by resisting torque imposed by the alternator in response to modulating the pulses of continuous current produced by the converted the alternating current.

FIELD OF THE INVENTION

The invention relates to a method of regulating operating parameters ofan installation for producing electric power comprising a wind machineand a device for carrying out the method.

BACKGROUND OF THE INVENTION

Installations are known for producing electric power from wind powerwhich comprise an alternator of which the rotor is driven by a rotatingpart of a wind machine having a hub and blades fixed on the hub.

In particular wind machines have been proposed in which the rotatingpart is connected directly to the rotor of the alternator withoutintermediate mechanical transmission. Such wind machines have theadvantage of a greater mechanical simplicity, the rotating assemblycomprising the rotating part of the wind machine integral with the rotorof the alternator being mounted so as to rotate on the structure of thewind machine via at least one block which may consist of one singlebearing, in an advantageous embodiment.

Furthermore, the elimination of mechanical elements such as reducerswith gears is reflected in a reduction in the costs of construction andof maintenance of the wind machine. Also the risks of breakdowns anddeterioration of certain parts of the wind machine, for example byseizing of the gearing of a reducer, are avoided. However, the drawbacksof a direct connection between the rotating part of the wind machine andthe rotor of the alternator are that the alternator must be able tooperate in a satisfactory manner at a low speed of rotation and that thevariable atmospheric conditions in which the wind machine functions, inparticular the wind speed, can bring about variations in the electricalparameters of the current supplied by the wind machine to an electricnetwork, these variations being generally unacceptable.

A particularly advantageous embodiment of the alternator of a windmachine used for the production of electric current uses an alternatorrotor having permanent magnets generally disposed in a field rotating inthe axial direction produced by the windings of a stator disposed facingthe rotor. The alternator has a generally discoid shape, the magnets ofthe rotor and the windings of the stator being distributedcircumferentially over surfaces in the form of discs.

French patent application FR-97 02808 filed by JEUMONT INDUSTRIE andFRAMATOME proposes the use of such a discoid alternator, the advantagesof which have been indicated in the description of the patentapplication, for the production of electric power by such a windmachine.

So as to obtain an electric current which is stable and of good qualityover the network supplied by the wind machine, it has also been proposedin the French patent application to associate with the alternator apower electronics module including a first ac-dc converter, such as arectifier, and a second dc-ac converter, such as an inverter, which areintended to supply a stable alternating current of good quality to thenetwork supplied by the wind machine.

The conversion of the alternating current produced by the alternator ofthe wind machine into direct current and the conversion of the directcurrent obtained into alternating current in effect permit freedom fromthe variations of operation of the wind machine due to the atmosphericvariations and make it possible to supply the network with a currenthaving a perfectly constant frequency (for example 50 Hz) with a verygood control of the voltage and of the power factor of the suppliedcurrent.

However, in the French patent application there is no description ofmeans permitting regulation of all the operating parameters of the windmachine, whether these parameters relate to the electrical operation ofthe alternator or are constituted by the speed of rotation of the rotaryassembly of the wind machine.

A first problem which is posed within the framework of operation of thewind machines relates to the protection of the rotary assemblycomprising the blades and the hub of the wind machine when the wind isvery strong and reaches speeds which are likely to bring about racing ofthe wind machine and deterioration of the rotary assembly and/or thebearings of this rotary assembly.

The wind machines must be produced in such a way as to ensuredisengagement of the rotating part when the wind speed exceeds a certainlevel; the performance of the blades of the rotary assembly then becomesvery poor and racing is avoided.

In the disengagement zone the increase in the power of the wind iscompensated for by a reduction in the performance of the blades;therefore the power is roughly constant.

An automatic disengagement is obtained for a certain wind speed due tothe profiling of the blades of the rotary assembly and a speed ofrotation which is imposed upon this rotary assembly. Such automaticdisengagement systems may be designated as “stall” systems and generallycomprise a rotary assembly in which the blades are mounted fixed on thehub.

Other systems, designated generally as “pitch” systems, use a rotaryassembly in which the blades are mounted so as to turn on the hub aboutan axis perpendicular to the axis of rotation of the rotary assembly,generally by means of a bearing which ensures the rotary mounting of thefoot of the blade, the device further comprising mechanical means whichensure the adjustment of the setting angle of the blade on the hub.These mechanical means are generally controlled in such a way that thesetting angle of the blade is adjusted continuously during the operationof the wind machine. In the case of a wind of which the speed exceeds apredetermined speed limit, the system ensures the disengagement of therotary assembly.

The “stall” system has the drawback of being definitely adjusted whenthe mounting of the blades on the hub of the rotary assembly has beenensured, as the disengagement is always effected for a predeterminedwind speed.

In fact, the regulation of the wind machine is carried out in such a waythat the rotary assembly turns at a nominal speed which is combined withthe wind speed to cause disengagement in conditions which can only bechanged by modification of the mounting of the blades on the hub inorder to vary the setting angle by pivoting the blades about theirlongitudinal axis. This operation of changing the setting angle of theblades must be carried out manually and necessitates stopping of thewind machine during a period which may be relatively long and theintervention of staff responsible for this operation on the rotatingpart of the wind machine.

Independently of the problems due to the disengagement by strong wind,it is desirable to adapt the setting angle of the blades to the climaticconditions in such a way as to obtain the best possible recovery of thewind power. Such an adaptation must be carried out as a function of theclimatic variations and, in particular, it is necessary to modify thesetting of the blades in order to change from hot-weather operation(summer) to cold-weather operation (winter).

In fact the cold winter air is denser than in summer, when the air iswarmer and lighter. Therefore the wind is more powerful during winter,such that it is desirable to modify the setting of the blades of thewind machines when the season changes. Such operations are ponderous andare reflected in operational losses both in terms of supply and sale ofelectric current. Provision may therefore be made not to modify thesetting of the blades but, in this case, the wind machine must bedimensioned for operation in the winter period, which involves a loss ofoperation in the summer period.

It is common to provide two different modes of coupling of the electricgenerator permitting it to function at two different nominal speeds ofrotation of the rotary assembly of the wind machine.

However, each of these two operating speeds is only adapted to one windspeed and, outside these ideal conditions, the power output of the windmachine is dissipated all the more as the conditions deviate from theideal operating conditions.

Another drawback of the wind machines in which the blades have a fixedsetting and which operate according to the fixed-speed “stall” system isthat it is necessary to reach the nominal speed of rotation of the windmachine before connecting the generator to the network in order to avoidconnection in conditions which are unacceptable for the network. It istherefore necessary to reach a sufficient level of power in order tostart to exploit the wind machine for the supply of current.

The systems of the “pitch” type in which the blades are mounted with acontinuously adjustable setting angle on the hub have appreciableadvantages relative to the device operating according to the fixed-speed“stall” system. In particular, these systems permit operation at fixedspeed or at variable speed and permit coupling to the network for lowwind speeds. However, such systems are extremely fragile due to themounting of the blades by means of a bearing and the use of a chain forregulation of the setting angle. A concentration of forces is producedon the blades, at the level of the bearing, and, due to the fact thatthe angles of rotation of the blades necessary for the setting aregenerally small, the bearing tracks undergo marking in the zone ofcontact with the bearing elements.

The setting angle regulating chain must include a means for control ofthe displacement of the blades which may be of the hydraulic, electricor electromechanical type. Such controls have a dynamic which isreflected in a relatively slow action of the regulating chain. Thereforethe orientation of the blades is not always at the ideal valuenecessitated by the operating conditions. For this reason, in certainphases insufficient power is recovered or, on the contrary, excessivepower is recovered, which brings with it drawbacks in the operation ofthe mechanical or electrical transmission of power.

The rotary assemblies of the wind machines must, on the other hand, beproduced in such a way that complementary braking of the wind machinecan be ensured, for example by normal stopping or accidental stopping,in combination with a mechanical braking system disposed on a shaft ofthe rotating part. Therefore the rotating part must include a brakingdevice, generally of the aerodynamic type.

In the case of a fixed-speed “stall” system, a braking element isprovided on the free end of the blades which is oriented in such a wayas to ensure aerodynamic braking.

In the case of a “pitch” system, the braking can be effected byfeathering of the blades by means of the setting angle regulating chain.

In one or the other case, when a micro-cutoff appears on the network,that is to say a cutoff of the circulation of the electric currentlasting typically less than a second, stopping of the wind machine mustbe commanded, by braking, in order to avoid any risk of deterioration ofthe electric generator. Following the stoppage, it is necessary toprovide a procedure for restarting so that this mode of operation withstopping of the wind machine is reflected in a loss of production andfatigue of the mechanical elements of the wind machine and in particularof the mechanical brake used for stopping and of the blades.

The electrical networks which ensure the distribution of current tousers require the voltage and the frequency of the current supplied tobe as constant as possible; in the case of a network supplied by a windmachine the said voltage and frequency depend upon the speed of rotationof the generator and thus of the wind machine.

In the case where it is necessary to provide a wind machine for anetwork using a frequency different from the usual frequency (forexample 60 Hz instead of 50 Hz), it is necessary to modify the generator(and possibly a multiplier) in order to adapt them to the requiredfrequency.

In the case of a network in which the frequency is not very stable andvaries relative to the predetermined nominal frequency, it is necessaryto adapt the operation of the wind machine.

If the frequency required on the network is higher than thepredetermined frequency, the speed of rotation of the wind machine mustincrease and consequently the power supplied increases.

If the frequency required on the network decreases, the speed ofrotation of the wind machine decreases and therefore the power supplieddecreases.

The power of the wind machine is not perfectly controlled, and for thisreason it is necessary to provide oversizing of the wind machine inorder to meet all the demands, which involves additional costs.

Finally, the rotary assembly of the wind machine does not turn at aperfectly constant speed and undergoes periodic variations due to thepassage of the blades of the rotary assembly in front of the mastsupporting the nacelle on which the rotary assembly is mounted.Therefore the current generator does not turn at a perfectly regulatedspeed ensuring perfectly stable and constant operation.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention, therefore, is to propose a method ofregulating an installation for producing electric power comprising anelectric alternator having a rotor integral with the rotating part of awind machine in order to constitute a rotary assembly, and a powerelectronics module including a means for converting the alternatingcurrent produced by the alternator into direct current, this methodmaking it possible to remedy the different drawbacks of the previoussystems which have been described above.

For this purpose the electrical characteristics (intensity, voltage,phase difference of intensity/voltage and frequency) of the electriccurrent produced by the alternator and the speed of rotation of therotary assembly are regulated by modulation of the continuous currentproduced by the conversion means of the power electronics modulestarting from the electric current produced by the alternator.

In a preferred manner:

in a first phase of operation of the installation for producingelectrical energy, for low wind speeds, the speed of rotation of therotary assembly of the wind machine is made to increase in such a waythat the speed of rotation passes progressively from a low startingvalue to a maximum value, the torque on the rotor increasing accordingto a predetermined law of speed/torque variation;

according to a first embodiment of the invention, in a second phase,when the wind speed is higher than a first threshold value the speed ofrotation of the rotary assembly of the wind machine is regulated at afixed maximum value, or nominal value, enabling optimum recovery ofpower by the wind machine to be obtained;

in this case, preferably, the nominal value of the speed of rotation isfixed at a value taken from amongst at least two values as a function ofclimatic conditions at the site of the wind machine and in particular ata first value in the summer period and at a second value in the winterperiod;

according to a second embodiment of the invention, in a second phase ofoperation of the wind machine, when the wind speed is higher than asecond threshold value the maximum speed of rotation of the rotaryassembly of the wind machine is regulated in such a way as to maintainthe power of the wind machine at a fixed value and, preferably, at themaximum power value acceptable by the wind machine;

in this case, preferably, when the value of the wind speed is lower thanthe second threshold value the speed of rotation of the rotary assemblyis made to increase in a progressive and regulated manner and thevariations in the value of the speed of rotation are recorded in such away that the curve representing the variation of the speed of rotationcan be used subsequently to control the increase in speed of the rotaryassembly.

The invention also relates to a regulating device consisting of a powerelectronics module and a regulating and control unit which enables themethod of regulation according to the invention to be carried out.

In order to aid understanding of the invention, a description will nowbe given, by way of example and with reference to the accompanyingdrawings, of a wind machine for producing electric power and of theimplementation of a method of regulation according to the invention invarious cases of operation of the wind machine.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic sectional view through a vertical plane of thenacelle of a wind machine for producing electric power.

FIG. 2 is a schematic view of the electrical part of the wind machineincluding in particular a power electronics module.

FIGS. 3A, 3B and 3C are diagrams showing the operation of a wind machineusing the “pitch” system for three different wind speeds.

FIGS. 4A, 4B and 4C are diagrams showing the operation of a wind machinecarrying out the method of regulation according to the invention forthree different wind speeds.

FIG. 5 is a schematic view of the rotary assembly of a wind machine andof the diagram of operation of a wind machine carrying out the methodaccording to the invention.

FIG. 6 is a diagram showing the variations of the coefficient ofperformance of a blade of the wind machine as a function of the angle ofincidence of the resultant of the wind speed and of the speed ofrotation of the blade.

FIG. 7 is a diagram giving the power supplied by the wind machine as afunction of the wind speed for different speeds of rotation of therotating part.

FIG. 1 shows the nacelle of a wind machine designated in general by thereference numeral 1 which is mounted so as to rotate, by means of arolling bearing 2 with a vertical axis, on the upper part of the mast 3of the wind machine.

DETAILED DESCRIPTION OF THE INVENTION

An antenna 4 bearing a wind telltale permits control of a motor fororientation of the nacelle 1 of the wind machine about the vertical axisof the mast 3 in order to orient it relative to the direction of thewind at any moment.

The nacelle 1 of the wind machine bears the rotary assembly of the windmachine which includes in particular a hub 5 on which three blades 6having a profiled section are fixed in a rigid manner.

The rotating part of the wind machine comprising the hub 5 and theblades 6 ensures that the rotor 8 of an electric current generator 7 isset in rotation, this electric current generator having a stator 9 fixedon a structural part 10 of the nacelle 1 integral with a platformmounted so as to rotate on the end of the mast 3 by means of thehorizontal bearing 2.

The rotor 8 and the stator 9 of the alternator 7 are produced in discoidform, the rotor 8 having two rotor elements placed on either side of thestator, each of the rotor elements having an active face in the form ofa disc bearing magnets distributed along the circumference of the disc.The stator 9 has two stator elements each having a discoid face on whichare fixed coils which are distributed circumferentially, each discoidface of a stator element being directed towards the correspondingdiscoid face provided with permanent magnets of an element of the rotor8.

In a typical manner, each of the rotor discs can have ninety magnetsdistributed circumferentially.

The rotary assembly of the wind machine comprising the rotating part ofthe wind machine and the rotor 8 of the alternator 7 is mounted so as torotate on the fixed structure 10 of the nacelle 1 by means of a singlerolling bearing 11 having an axis slightly inclined relative to thehorizontal direction.

The windings of the stator 9 are connected electrically to connectingmeans which permit the current supplied by the wind machine to be sentover a utilization network by means of a power electronics module whichcan be disposed at least partially in the interior of the nacelle 1.

FIG. 2 shows schematically the power electronics module which isdesignated generally by the reference numeral 12 and permits recovery ofthe electric current produced at the output of the alternator 7 of whichthe rotor 8 is driven in rotation by the rotating part 5, 6 of the windmachine and permits the supply to an electric utilization network 13 ofan alternating electric current via a transformer 14.

The current produced by the alternator 7 and the current supplied to thenetwork are three-phase alternating currents.

Each of the phases at the output of the alternator 7 is connected to theinput of the power electronics module and each of the phases of thethree-phase current at the output of the power electronics module isconnected to the input of the transformer 14.

The power electronics module designated generally by the referencenumeral 12 comprises in succession a rectifier 15 which ensures theconversion of the alternating current produced by the alternator intodirect current, a rheostatic chopper 16 and an inverter 17.

The rectifier 15 and the inverter 17 are connected to one another by adirect current bus 18 joining the output of the rectifier 15 to theinput of the inverter 17. The rheostatic chopper 16 is mounted inparallel on the bus 18, between the rectifier 15 and the inverter 17.

The rectifier 15 is a pulse width modulating (PWM) rectifier whichpermits modulation of the width of the direct current pulses producedfrom the alternating current of the alternator 7, the period of thedirect current pulses being constant and for example equal to 1000 Hz.

The rectifier 15 comprises three processing stages each connected to aphase of the alternator 7 and each having two insulated gate bipolartransistors (IGBT), each of the IGBT transistors being controlled insuch a way as to ensure or prohibit the passage of the current of thedifferent alternations of the three phases of the alternating current ofthe alternator 7.

FIG. 2 shows a digital control and regulating unit 20 which permitscontrol of each of the IGBT transistors of the PWM rectifier 15. All ofthe controls of the transistors of the pulse width modulating rectifier15 are represented in the form of the arrow 21.

The inverter 17 is produced in a form analogous to that of the rectifier15 and the arrangement of its components is the reverse of that of therectifier 15, in such a way that it can transform a direct current bymodulated pulses into a three-phase alternating current having aperfectly controlled voltage and frequency and that it is thus possibleto supply to the network 13 via the transformer 14 a three-phasealternating current having perfectly fixed voltage and frequency, thisfrequency being for example 50 Hz for distribution over the Frenchnetwork.

The inverter 17 is controlled by the digital control and regulatingmodule 20, as shown schematically by the arrow 22.

The control and regulating module 20 receives as input data coming fromthe alternator 7 (input symbolized by the connecting line 23) theintensity I and the voltage U of the electric current in each of thephases at the output of the alternator 7 as well as the speed ofrotation co of the rotor of the alternator which is measured by arotation measuring device of a known type.

The measurements reach the control and regulating module 20 in the formof signals. It should be noted that the speed of rotation co of therotor is also the speed of rotation of the rotating part 5, 6 of thewind machine.

The control and regulating module 20 also receives, as shownschematically by the arrow 24, a signal representing the direct currentvoltage in the bus 18.

On each of the phases at the output of the inverter 17 there is disposeda means 26 for measuring the intensity of the current of thecorresponding phase, and between two phases at the output of theinverter 17 there is also disposed a transformer 27 for measuring thevoltage of the three-phase current.

The corresponding intensity and voltage signals are transmitted to thecontrol and regulating module 20, as shown schematically by theconnecting line 25.

The control and regulating module 20 is also connected to the rheostaticchopper 16 in order to ensure the control of the rheostatic chopper, asindicated by the connecting line and the arrow 28.

In a general manner, on the basis of the measurement signals of thevoltage U of the current produced by the alternator and the signals ofthe currents I in each of the phases as well as a signal representingthe speed of rotation of the rotary assembly of the wind machinecomprising the rotor 8 of the alternator 7, the digital control andregulating module 20 ensures modulation of the direct current by pulsesproduced in the PWM rectifier 15.

As indicated above, this modulation consists of regulating the width ofthe direct current pulses of which the frequency remains fixed and equalfor example to 1000 Hz.

This modulation of the pulse width of the direct current produced in therectifier permits, by reaction, regulation of the amplitudes of theintensities and of the voltage of the current produced by thealternator, as well as the phase difference (p of the voltage U relativeto the intensity I of the current.

Thus by modulation of the direct current produced by the rectifier it ispossible to regulate the electrical operating parameters of thealternator 7, either in order to obtain ideal electrical operation ofthe alternator 7 or to regulate the speed of rotation co of the rotatingassembly of the wind machine comprising the rotor of the alternator 7,by means of the resisting torque of the alternator.

The inverter controlled by the control and regulating unit 20 whichreceives a signal representing the intensities and voltages of thecurrent at the output of the inverter 17 makes it possible to regulate,by pulse width modulation, the three-phase alternating current at theoutput of the inverter 17.

It should be noted that the transformation of the alternating currentproduced by the alternator 7 into direct current in the rectifier 15 andthe subsequent conversion of the direct current into alternating currentin the inverter 17 permits a complete dissociation of the conditions ofproduction of the alternating current at the output of the alternatorwhich depend upon the speed of the wind machine from the conditions ofproduction of the alternating current at the output of the inverterwhich become totally independent of the speed of rotation of therotating part of the wind machine. Thus it is possible to supply thenetwork, by means of the transformer 14, with an electric current at avoltage and a frequency which are perfectly fixed, the voltage and thefrequency of the current produced by the alternator being, on the otherhand, essentially variable as a function of the wind driving the windmachine.

The measurement of the voltage U and of the intensity I at the output ofthe alternator 7 makes it possible to obtain the fluctuations over thecourse of time of the power which is supplied by the alternator. Thesefluctuations can be used in the control unit 20 in order to anticipatethe control of the inverter 17 in order to limit the fluctuations of thevoltage in the direct current bus 18.

The signals relating to the parameters of the three-phase alternatingcurrent supplied to the utilization network 13 and transmitted to thecontrol and regulating unit 20 by the connecting line 25 also make itpossible to envisage anticipating the regulation of the chopper as afunction of disruptions of the current in the network.

The voltage in the direct current bus 18 is measured and transmitted tothe control and regulating unit in the form of a signal which permitsthe unit 20 to control the rheostatic chopper 16 in such a way as toregulate the transmission of the direct current to the inverter 17.

In the case where the current is no longer drained in a regular mannerby the network at the output of the inverter 17, the voltage increasesin the direct current bus 18 and the regulating unit 20 controls therheostatic chopper 16 in such a way as to cut off the current producedand to allow only a part of the direct current to pass, the residualcurrent being diverted over the rheostat 29 of the rheostatic chopper16. In this way the excess power produced by the wind machine isabsorbed during a failure of the network. This regulation can beanticipated by virtue of the measurements carried out at the output ofthe inverter 17 and transmitted to the control and regulating unit 20.

In the course of its operation, the wind machine is controlled accordingto distinct successive phases of regulation, as a function of the speedof rotation of the rotary assembly of the wind machine which is itself afunction of the wind speed.

For low wind speeds, up to about a maximum speed or nominal speed, thatis to say from the starting speed of the wind machine for the productionof electric power, which speed can be very low, up to a wind speeddriving the rotary assembly at the nominal speed (defined for a givenpower, for example 25 rpm), the electrical parameters of the alternatorare regulated and, by means of these, the speed of rotation of the rotorand of the rotary assembly and the torque on the rotor are regulated insuch a way that the points of operation are situated on a perfectlydefined torque/speed curve. This curve has substantially the shape ofslightly inclined straight line, the torque increasing very little fromthe lowest speeds of rotation up to the maximum speed.

The speed of rotation of the rotary assembly comprising the rotor of thealternator can be easily regulated on the basis of the resisting torqueimposed by the alternator which itself depends upon the electricalparameters of the current at the output of the alternator, theseparameters being regulated by modulation of the rectifier.

We will now show how the control of the speed of rotation of the rotaryassembly of the wind machine makes it possible to make the wind machineoperate during this first phase in an optimal manner with maximumtransmission of power as a function of the wind speed.

By way of comparison, FIGS. 3A, 3B and 3C show diagrams of the speedalong the profile of a blade 6′ of a wind machine according to the priorart comprising a rotary assembly of which the blades include a means forcontinuous adjustment of the setting angle.

FIGS. 4A, 4B and 4C show corresponding diagrams in the case of a blade 6mounted fixed on the rotary part of the wind machine which is regulatedby the method according to the invention.

In FIGS. 3A, 3B and 3C and also in FIGS. 4A, 4B and 4C, the vectors{right arrow over (V)}1, {right arrow over (V)}2 and {right arrow over(V)}3 represent the wind speed to which the wind machine is subjected inthe course of three phase of use, {right arrow over (V)}1 correspondingto an average wind speed, {right arrow over (V)}2 to a strong wind and{right arrow over (V)}3 to a slight wind.

The vectors {right arrow over (ω)}R in FIGS. 3A, 3B and 3C represent thelinear speed of a blade at a distance R from the axis of rotation, orradius, for a speed of rotation ω of the rotary assembly of the windmachine, this speed of rotation ω being regulated at a constant valueequal to the nominal speed of operation of the wind machine (for a givenspeed), regardless of the wind speed.

In FIGS. 4A, 4B and 4C the vectors ω{right arrow over (1)}R, ω{rightarrow over (2)}R and ω{right arrow over (3)}R represent the linearspeeds of the blades of the wind machine regulated using the methodaccording to the invention, in the course of three phases at averagewind, strong wind and slight wind, the speeds of rotation ω1, ω2 and ω3being modulated by control of the PWM rectifier of the power electronicsmodule as described above.

The vectors {right arrow over (W)}1, {right arrow over (W)}2 and {rightarrow over (W)}3 represent, both in FIGS. 3A, 3B and 3C and in FIGS. 4A,4B and 4C, the resultant of the speeds of the wind and of the blades ofthe rotary assembly of the wind machine in the course of the threephases under consideration.

Also shown in all of the drawings in the longitudinal direction L of thesection of the blade 6 or 6′, the resultant of the speed of the wind andof the blade in rotation making with the longitudinal direction L of thesection of the blade 6 or 6′ an angle of attack I as a function of whichthe performance f=Cz/Cx of the blade in question varies as shown in FIG.6. Due to the fact that the blades are twisted, the angle (α1, α2, α3 orα) between the longitudinal direction L of the blade and the speedvector of the blade varies along the blade. Therefore the angle ofattack is not constant along the length of the blade.

It will be seen in FIG. 6 that the curve 30 representing the variationsin the performance f=Cz/Cx of the blade of a wind machine as a functionof the angle of attack i is increasing up to an optimum value i forwhich the performance of the vane reaches a maximum. The performance ofthe vane then decreases when i increases, first of all in a moderatemanner, then very rapidly, in a zone 31 corresponding to a zone ofdisengagement of the rotating part of the wind machine, the powersupplied by the wind machine subsiding to a very low value or evenpractically zero.

It is therefore necessary, in order to obtain a good output of powerfrom the rotary assembly of the wind machine, to operate with values ofthe angle of attack i close to the optimum value i giving the maximumperformance of the blades.

In the case of a wind machine operating according to the “pitch” systemwith continuous adjustment of the orientation of the blades, an angle iis obtained which is substantially constant and equal to the optimumangle of attack i regardless of the wind speed (within certain limits)causing the vane to turn in one direction or the other.

When there is a change from a wind of average speed {right arrow over(V)}1 to a wind at high speed {right arrow over (V)}2 the blade 6′ ismade to turn in such a way as to increase the angle of the longitudinaldirection L of the blade with the speed vector of the blade {right arrowover (Ω)}R (the angle passes from the value α1 to the value α2), suchthat the angle of attack i remains constant.

In the case where there is a change from wind at average speed {rightarrow over (V)}1 to a wind at low speed {right arrow over (V)}3 theblade 6′ is made to turn in such a way as to decrease the angle betweenthe longitudinal direction L of the blade and the speed vector of theblade {right arrow over (ω)}R, this angle passing from the value α1 tothe value α3 in such a way that the angle of attack i remainspractically constant.

An indication has been given above of the drawbacks of such a device inwhich it is necessary for the blades, of which the foot is mounted so asto rotate on the hub of the wind machine by way of a bearing, to be madeto turn.

In the case of a method of regulation according to the invention asshown in FIGS. 4A, 4B and 4C, it is possible to regulate the speed ofrotation ω and therefore the linear speed ωR of the blade as a functionof the wind speed in order to keep the angle of attack i practicallyconstant and equal to the optimum value.

In the case where there is a change from a wind of average speed V1 to awind at high speed V2, the speed of the blade is allowed to increase upto a value ω2R which is imposed by the resisting torque of thealternator of which the electrical parameters are regulated bymodulation of the direct current produced by the rectifier of the powerelectronics module. The value ω2R of the speed of rotation of the bladecan be adjusted in such a way that the angle of attack i (and the angleα of the blade with the speed vector of the blade) remains practicallyconstant, the angle of attack i remaining at its optimum value.

When there is a change from a wind at average speed VI to a wind at lowspeed V3, the speed of rotation of the rotary assembly of the windmachine is made to decrease to a value ω3R such that the angles i and aremain constant, the angle i being at its optimum value.

The reduction in the speed of the rotary assembly and of the rotatingpart of the wind machine is obtained by regulating the electricalparameters at the output of the alternator, by modulation of the directcurrent produced by the PWM rectifier, such that the resisting torque ofthe alternator is increased.

In the first phase of operation of the wind machine, the wind speedchanges from a low value, corresponding to the wind machine starting toproduce electricity, to a maximum value acceptable to the wind machine,corresponding to the nominal speed of the rotary assembly of the windmachine, and the speed of rotation of the wind machine is allowed toincrease in such a way as to keep the point of operation of the bladesclose to the maximum of the curve of performance of the blades. Asindicated above, the torque on the rotor increases slightly.

Then the nominal speed of rotation of the rotary assembly of the windmachine (for example 25 rpm) is reached, this value being obtained for athreshold value of the wind speed, the speed of rotation is regulated ata fixed value which is the nominal speed of the wind machine, and thetorque then increases very rapidly once the nominal speed has beenreached.

In a diagram showing the torque as a function of the speed, this phaseis represented by a torque variation curve which is practically parallelto the axis of the torques and perpendicular to the axis of the speeds.

With reference to FIG. 5, in which the rotating part 5, 6 of a windmachine is shown as well as the speed diagram following the section of ablade 6, it may be supposed that the vector {right arrow over (ω)}Rcorresponds to the nominal speed of rotation of the rotating part 5, 6of the wind machine for the wind speed V.

If the wind speed increases beyond the value V (for example it reachesthe speed V4), the speed ωR remaining constant, the angle of attack iincreases up to the value i_(d) corresponding to the disengagement onthe curve of FIG. 6. In this way a stall is obtained at a wind speedwhich is determined by the value of the nominal speed ω. In reality, dueto the fact that the angle of attack i varies with the radius R aprogressive disengagement of the blade is obtained when the windincreases.

When it is wished to change the speed at which the disengagement takesplace, the nominal speed of rotation ω can be modified, for example byincreasing the speed of rotation in order to increase the speed ofdisengagement or by reducing the speed of rotation in order to reducethe speed of disengagement.

Thus a stall is obtained at variable speed by a simple modification ofthe control of the rectifier of the power electronics module associatedwith the alternator of the wind machine.

It is possible to make the nominal speed change, for example from asummer value to a winter value, without having to effect a new settingof the blades of the rotating part of the wind machine.

Thus the stall of the wind machine can be adapted to the climaticconditions and in particular it is possible to effect a change of thenominal speed of the rotary assembly of the wind machine between asummer value and a winter value, or vice versa.

FIG. 7 shows a set of curves 32 a, 32 b, 32 c, 32 d, 32 e, 32 f, 32 g,32 h, 32 i, 32 j, 32 k, 32 l showing the variations in the mechanicalpower supplied by the wind machine as a function of the speed of thewind driving the rotating part of the wind machine in rotation and forimposed nominal speeds of rotation of respectively 9; 12; 15; 18; 21;23; 24; 24.5; 24.8; 25; 25.5 and 28 rpm.

A curve 33 is also shown which corresponds to an optimized regulation ofthe speed of rotation regardless of the wind speed in order to obtainoptimum operation of the wind machine, with a level at a nominal powerof 800 kW.

In order to obtain a mechanical power of the wind machine of 800 kW(that is to say the power available over the rotating part driven by thewind), FIG. 7 shows that the nominal speed of rotation can be fixed at24 rpm as soon as the wind speed reaches a first threshold at 9 m/sec.Between the starting speed of the rotating part and 9 m/s, the speed ofrotation of the rotating part of the wind machine increases according toa well defined torque/speed curve in such a way as to optimize thepower. Above the wind speed of 9 m/s the speed is regulated in order tokeep it at the value of 24 rpm by modulation of the direct currentobtained from the current produced by the alternator. The mechanicalpower supplied by the wind machine develops as a function of the windspeed, as shown by the curve 32 g. It will be seen that the power of 800kW is only obtained for two wind speeds (14 and 25 m/s). Between thespeeds of 14 and 25 m/s the power drops slightly, such that a level ofpower at 800 kW is not obtained. It is also possible, in the secondphase of operation of the wind machine, to regulate the speed ofrotation of the wind machine in order to obtain a 800 kW power level. Aregulation of the power is then effected at variable speed of rotation,in such a way that the mechanical power supplied by the wind machine isconstant for wind speeds ranging from 11.5 to 25 m/s, as shown by thecurve 33. Between the first and the second thresholds of the wind speed(9 to 14 m/s) the speed of rotation of the rotary assembly is made toincrease in a progressive and regulated manner. In fact, this zone is azone of transition between engagement and disengagement of the blades inwhich the wind machine must be controlled prudently. Control software isgenerally used, while recording the variations in the speed of rotationin order to enhance the database relating to the rises to the 800 kWpower level effected on the site of the wind machine, which depend uponthe climatic conditions encountered. These data are used duringsubsequent rises in speed and in power of the wind machine. Thereforeself-adaptation is obtained.

The speed is controlled between the two wind speed thresholds in such away as to obtain a maximum power. This control is called aggressivecontrol. The curve 33 corresponds to the optimized operation of the windmachine for all wind speeds.

Above the second threshold of the wind speed (14 m/s), there is nolonger any risk of racing of the rotary assembly and the speed ofrotation is continuously adapted in order to obtain a power of 800 kW.

The method according to the invention makes it possible to adapt thespeed of rotation in a very flexible manner by electronic means.

The electrical parameters at the output of the alternator 7 areregulated in such a way that the alternator has optimum operatingconditions. Under these conditions the intensity i of the current of thealternator and the internal voltage or open circuit voltage E of thealternator are perfectly in phase. Thus the electrical conditions arepermanently regulated in order to obtain a zero phase difference betweenthe intensity and the internal voltage of the alternator by regulatingthe intensity/voltage phase difference taking account of the inductanceof the alternator.

Thus the method according to the invention makes it possible, by simpleregulation of the direct current produced by the PWM rectifier, toobtain ideal electrical and mechanical conditions of operation of thealternator and of the wind machine.

In the disengagement zone, the regulation of the speed by the methodaccording to the invention may make it possible to obtain a perfectlyconstant power. This avoids having to oversize the wind machine in orderto stand up to local power surges.

After disengagement by a stall effect at a certain wind speed, it ispossible to restore the capacity of the wind machine to operate atnominal power by acting on the speed of rotation of the rotating part.

With reference to FIG. 5, an explanation can also be given as to how thenormal electric stopping of the wind machine is effected, that is to saythe electric braking of the wind machine between its nominal speed and aspeed of substantially zero.

Assuming the wind speed V constant during the electric stopping of thewind machine, this stopping is obtained by regulating the resistingtorque of the alternator in order progressively to decrease the speed coof rotation of the rotary assembly of the wind machine.

The electric braking of the wind machine by means of the resistingtorque of the alternator is obtained in a very gradual manner, byimposing a torque greater than the nominal torque in a relatively lowproportion, for example of the order of 10%. By way of comparison, inthe case of the earlier devices it is necessary to double the resistingtorque in order to obtain an effect of braking of the wind machine fromthe nominal speed.

In the case of the electric braking carried out according to theinvention, the stall effect is added very rapidly to the reduction inthe speed by electric braking by means of the resisting torque of thealternator, in order to bring about a reduction in the power of the windmachine which changes from its nominal value to a value of practicallyzero.

In fact, as can be seen in FIG. 5, when the speed ω is decreased, thewind speed V being constant, the resultant {right arrow over (W)} of thewind speed and of the linear speed {right arrow over (ω)}R makes anincreasing angle of attack i with the longitudinal direction L of theblades of the wind machine. Thus stall conditions are obtained when theangle i reaches the disengagement value i_(d).

The reduction in the speed ω by electric braking is effectedprogressively in such a way that the excess power in the network 13connected to the wind machine can be drained without the voltage in thedirect current bus 18 reaching the level of triggering the rheostaticchopper 16.

The conditions of production of three-phase alternating current by theinverter 17 from direct current are such that the parameters of thethree-phase current sent over the network 13 can be regulatedindependently of the operation of the alternator 7 which is itselfregulated by the PWM rectifier 15.

Thus it is possible to make the wind machine operate either as aconventional current generator, the cosine φ being capable of beingadapted to the requirements of the operator, or as a synchronouscompensator, the wind machine supplying the network 13 with a reactivepower in the desired quantity in order to meet the requirements of theoperator of the network 13.

This avoids placing compensating units on the network 13 in the case ofa requirement for reactive current.

It should be noted that the inverter 17 operates in a manner analogousto that of the PWM rectifier 15, in the reverse direction, whereby theinverter 17 produces from a direct current by pulses supplied by thedirect current bus 18 a three-phase alternating current of which theelectrical parameters can be regulated from the control line 22 of theinverter connected to the control and regulating unit 20.

Because the power electronics module 12 associated with the wind machineis entirely symmetrical, and because the rectifier 15 and the inverter17 disposed on either side of the chopper 16 can operate in a reversiblemanner, it is possible to use the network 13 to supply, via thetransformer 14, the inverter 17 which then functions as a rectifier andsupplies at its output a direct current by pulsing which is transmitted,by the bus 18 connected to the chopper 16, to the rectifier 15 whichthen functions as an inverter in order to supply an alternating currentto the alternator 7 which then functions as a synchronous motor drivingthe rotating part 5, 6 of the wind machine.

When the wind machine is stopped it is possible to change its speed to astarting speed of the alternator 7 by controlling the rectifier 15functioning as an inverter and supplied with direct current by means ofthe network and the inverter 17 functioning as a rectifier.

Thus it is possible to produce very flexible starting conditions withideal coupling to the network, the operation of the wind machine and ofthe alternator 7 to produce electrical energy only being activated atthe moment when the ideal starting speed of the alternator is reached;this speed can be relatively low because of the possibilities of controlof the wind machine at variable and increasing speed during its firstphase of operation in order to reach the nominal speed, as indicatedabove.

Thus it is possible to design blades of which the profile is createdquite independently of the starting conditions of the wind machine. Theblades of a wind machine generally have a cylindrical blade foot fixedon the hub and a profiled part of which the profile becomes thinner, inthe longitudinal direction of the blade, as the distance from the footof the blade increases. In order to obtain a sufficient starting torque,it is necessary to design blades of which the profiled part has asubstantial width (in a radial direction such as L in FIG. 5) in thevicinity of the cylindrical part for connection to the hub.

As the wind machine can be started using the alternator as a motor, itbecomes possible to use blades of which the profiled part has a smallerwidth in its zone close to the cylindrical part for connection to thehub. This limits the forces exerted by the wind on the blades of whichthe widest part in the vicinity of the cylinder for connection to thehub offers a greater resistance to the wind. The blades therefore resiststrong winds better and it becomes possible to envisage lightening ofthe structures downstream of the blades (in particular the hub, thenacelle and the mast).

When the wind machine is stopped, the method and the apparatus forcontrol of the wind machine according to the invention make it possibleto employ an ideal means for regulating the conditions of keeping thewind machine stopped when the rotor is a rotor with permanent magnets.

The alternator including a rotor with permanent magnet has couplingmeans such as one or several switches which make it possible to connectthe phases of the alternator to one another.

After a normal (or incidental) stopping of the rotary assembly of thewind machine, the switch is toggled such that the short-circuiting ofthe alternator, of which the rotor with permanent magnet continues toexert a magnetic field, produces a resisting torque which opposes a risein the speed of rotation of the rotary assembly of the wind machine. Forthis reason a disengagement of the blades from the rotating part of thealternator is produced very quickly, as was explained with regard toFIG. 5. The disengagement is all the more rapid and substantial as thewind becomes stronger. Therefore the wind can only exert a very limitedtorque on the rotor and the rotary assembly of the wind machine, whichis reflected in a rotation at very low speed of the rotating assembly.This operation at very low speed is perfectly stable due to the electricbraking of the alternator and the disengagement of the blades whichincreases as soon as the wind becomes stronger. Therefore perfectsecuring of the stopping of production by the wind machine is thusobtained, and the rotary assembly then rotates at a speed substantiallylower than the speed of rotation for the production of electric energy(for example two to three rpm). This slight rotation of the alternatormakes it possible to avoid marking of the rolling tracks of the rotorbearing, as the turning elements of the bearing move along the entireperiphery of the rolling tracks.

The very low electric power produced by the alternator during thisrotation at low speed which dissipates in the windings of the stator ofthe alternator makes it possible to keep the alternator at temperature,which avoids any problem of condensation on the elements of thealternator, regardless of the atmospheric conditions.

The rheostatic chopper 16 placed in parallel on the direct current bus18 connected to the output of the PWM rectifier 15 and to the input ofthe PWM inverter 17 makes it possible to regulate the transmission ofelectric power between the alternator and the network.

When the network 13 cannot drain all of the power supplied by thealternator 7, the voltage in the direct current bus 18 increases and acorresponding signal is sent by the line 24 to the digital control andregulating unit 20. The control and regulating unit 20 transmits acontrol signal to the rheostatic chopper via the line 28 in such a waythat the rheostatic chopper cuts off the direct current and drains partof the electric power over the rheostat 29, in such a way as to balancethe transmission of power between the alternator and the network.

In particular, the rheostatic chopper 16 can be used to drain thetransient energy coming from the PWM rectifier in the event of ashort-term failure of the network, such as a micro-cutoff lasting lessthan a second, or in the case of a malfunction of the inverter, orduring incidental stopping of the wind machine.

In the event of a micro-cutoff appearing on the network 13, that is tosay a cutoff of the network for a period typically lasting less than asecond, the network can no longer drain the electric power coming fromthe power electronics module 12 and the voltage in the direct currentbus 18 increases because the PWM rectifier continues to supply directcurrent obtained by conversion of the alternating current of thealternator 7.

The control unit 20 receives the information about the rise in voltageof the direct current bus 18 via the line 24 and transmits an activationcommand to the chopper 16 via the line 28. The chopper drains a part ofthe electric power which reaches it via the direct current bus 18 overthe rheostat 29. The system returns to a predetermined minimum powerthreshold and if this power threshold is maintained the normal operationof the wind machine resumes.

If the power continues to increase above the predetermined threshold,due to the persistence of a fault in the network 13, a new operation iscarried out of absorption of power in the rheostat 29 of theelectrostatic chopper.

When the fault persists for a period typically lasting longer than asecond, incidental stopping of the wind machine is effected.

In the event of an incident or an accident reflected in a lasting faulton the network 13 or the inverter 17, the wind machine is stopped byactivation of the procedure for stopping by electric braking which wasdescribed above and by mechanical braking.

Unlike normal stopping, of which the progressive procedure can beprogrammed in such a way as to drain the power over the network duringan incidental or accidental stoppage, the power produced by thealternator and transmitted by the rectifier is drained in the rheostat29 of the chopper.

The braking is ensured until disengagement of the rotary assembly of thewind machine, as described previously.

The invention is not strictly limited to the embodiment which has beendescribed.

Thus the power electronics module may comprise elements different fromthose indicated above, starting from the moment when this powerelectronics module in an intermediate phase effects the conversion ofthe alternating current of the alternator of the wind machine intodirect current using a means of which the current can be modulated inorder to regulate by reaction the electrical parameters at the output ofthe alternator.

The alternator of the wind machine may be different from an alternatorhaving a rotor with permanent magnets. However, in order for theinvention to be carried out the rotor of the alternator must permittorque control. The rotor can be a wound rotor having electric windingsand for example produced in the form of a wound rotor of the synchronoustype. In the case of a rotor with permanent magnets an additionaladvantage is obtained, since it is possible to effect braking of therotating part of the wind machine on stopping.

The alternator and the wind machine can be of any type and can have anypower. The method and the device according to the invention are welladapted in particular to the case of high-power wind machines andalternators, for example power close to 1 MW or higher.

1. A method of regulating a system that produces electric power, thesystem including an electric alternator having a rotor integral with arotating part of a wind machine to form a rotary assembly, and a powerelectronics module, the method including the steps of: producing analternating current at output terminals of the alternator and havingelectrical characteristics, including amperage, voltage, phasedifference between current and voltage, and frequency; converting thealternating current produced by the alternator into modulated pulses ofdirect current, wherein the electrical characteristics, includingamperage, voltage, phase difference between current and voltage, andfrequency, of the alternating electric current produced by thealternator are regulated, by controlling the speed of rotation of therotary assembly by resisting torque imposed by the alternator inresponse to modulating the pulses of continuous current produced by theconverted alternating current; wherein, when wind speed is higher than afirst threshold value, the speed of rotation of the rotary assembly ofthe wind machine is regulated at a fixed maximum value, or a nominalvalue, enabling optimum recovery of power by the wind machine.
 2. Themethod of regulating as claimed in claim 1, wherein during a first phaseof operation of the system, for low wind speeds, the speed of rotationof the rotary assembly of the wind machine is made to increase in such away that the speed of rotation passes progressively from a low startingvalue to a maximum value, the torque on the rotor increasing accordingto a predetermined law of speed/torque variation.
 3. The method asclaimed in claim 1, wherein during a second phase of operation of thewind machine, when the wind speed is higher than a second thresholdvalue the maximum speed of rotation of the rotary assembly of the windmachine is regulated in such a way as to maintain the power of the windmachine at a fixed value and, preferably, at the maximum power value ofthe wind machine.
 4. Method as claimed in claim 3, wherein, when thevalue of the wind speed is lower than the second threshold value thespeed of rotation of the rotary assembly is made to increase in aprogressive and regulated manner and the variations in the value of thespeed of rotation are recorded in such a way that a curve representingthe variation of the speed of rotation can be used subsequently tocontrol the increase in speed of the rotary assembly.
 5. The method asclaimed in claim 1, wherein the electrical characteristics of theelectric current produced by the alternator are regulated in such a waythat the internal open circuit voltage of the alternator is in phasewith the amplitude of the current.
 6. The method as claimed in claim 1,wherein the maximum speed of rotation of the rotary assembly of the windmachine is regulated at a value permitting disengagement of the bladesof the rotating part of the wind machine for a predetermined wind speed,by modulating the pulses of continuous current produced by saidconversion.
 7. The method as claimed in claim 1, wherein the nominalvalue of the speed of rotation is fixed at a value taken from amongst atleast two values as a function of climatic conditions at the site of thewind machine and in particular at a first value in a summer period andat a second value in a winter period.
 8. The method as claimed in claim1, wherein the direct current is converted and used to supply analternating current to a utilization network and that the electricalparameters of the alternating current supplied to the utilizationnetwork are regulated by control of the conversion of the direct currentinto alternating current.
 9. Method as claimed in claim 8, wherein theregulated electrical parameters of the alternating current supplied tothe network include the cosine φ and the reactive power of the currentsupplied to the network.
 10. The method as claimed in claim 1, whereinthe electric power transmitted after conversion of the alternatingcurrent into direct current and subsequent conversion of the directcurrent into alternating current are regulated by cutoff of the directcurrent transmitted between the conversion of the alternating currentinto direct current and the conversion of the direct current intoalternating current and for diverting at least a part of the electriccurrent through a rheostat.
 11. Method as claimed in claim 10, wherein amicro-cutoff occurs on the electrical network lasting for a period lessthan a fixed limit, the electric current is cut off and at least a partof the current is diverted in order to drain the electric power from thealternator during the micro-cutoff of the network.
 12. The method asclaimed in claim 10, wherein, in the event of a cutoff of the electricalnetwork for a period lasting longer than the fixed limit or amalfunction during alternating current production, stopping of thesystem for producing electric power is brought about at least partiallyby electric braking, based on the resisting torque, and excess electricpower produced by the alternator being drained in a rheostat of thedevice for cutting off the direct electric current produced by the meansfor conversion of the alternating current of the alternator into directcurrent.
 13. The method as claimed in claim 1, wherein the wind machineis stopped in order to change the speed of the rotary assembly from anominal speed to a low speed of practically zero by effecting electricbraking of the rotary assembly by increasing the resisting torque of thealternator by regulating the electrical parameters of the currentproduced by the alternator in a progressive manner, and that excesspower is drained over at least a part of the network supplied by thesystem for producing electric current and a rheostat.
 14. The method asclaimed claim 1, wherein the alternator having a rotor with permanentmagnets is short-circuited after shut down of the system for producingelectric current, in such a way as to create a resisting torque opposingan increase in the speed of rotation of the rotary assembly in order toobtain a speed of rotation of the rotary assembly which is substantiallylower than a speed of rotation during operation of the system forproducing electric power.
 15. The method as claimed in claim 1, whereinthe starting of the wind machine is effected initially while stopped, bycausing the alternator to function as a synchronous motor supplied bymeans of the power electronics module in such a way as to drive therotating part of the wind machine at a starting speed of the alternator.16. A device for regulating an installation for producing electric powercomprising an electric alternator having a rotor integral with therotating part of a wind machine in order to form a rotary assembly, apower electronics module including a means for converting thealternating current produced by the alternator into direct current, andmeans for measuring the amperage and voltage of the current produced bythe alternator and the speed of rotation of the rotary assembly, whereinthe means for conversion of the alternating current produced by thealternator into direct current is a pulse width modulating rectifierconnected to a digital control and regulating unit regulating the directcurrent by pulses produced by the pulse width modulating rectifier as afunction of the measurement of said amperage and voltage of the currentproduced by the alternator and said speed of rotation of the rotaryassembly.
 17. Device as claimed in claim 16, wherein the powerelectronics module also comprises a pulse width modulating inverterconnected to an output part of the pulse width modulating rectifier byat least one direct current bus having an output part connected to anetwork utilizing an alternating current produced by the pulse widthmodulating inverter from the direct current, the pulse width modulatinginverter being connected to the digital control and regulating unitreceiving a measurement of the voltage of the alternating currentsupplied to the utilization network in order to regulate the electriccurrent supplied by the pulse width modulating inverter to the network.18. Device as claimed in claim 16, wherein the power electronics modulealso comprises a rheostatic chopper connected to the output part of thepulse width modulating rectifier and to a direct current input part ofthe pulse width modulating inverter, the rheostatic chopper beingconnected to the digital control and regulating unit which receives asignal representing the voltage in the direct current bus connecting theoutput part of the pulse width modulating rectifier to the rheostaticchopper in such a way as to control the cutoff of the electric currentpassing through the rheostatic chopper and the diversion of at least apart of the electric current to a rheostat during an increase in thevoltage in the direct current bus.
 19. Device as claimed in claim 16,wherein the rotor of the electric alternator is a rotor with permanentmagnets and that the electric alternator includes means for couplingphases of the alternator to one another.
 20. Device as claimed in claim16, wherein the rotor of the electric alternator is a wound rotor and inparticular a synchronous wound rotor.
 21. A method of regulating aninstallation for producing electric power, the installation having anelectric alternator having a rotor integral with a rotating part of awind machine forming a rotary assembly, and a power electronics module,the method comprising the steps: producing an alternating current at theoutput of an electric alternator and having electrical characteristics,including amperage, voltage, phase difference between current andvoltage and frequency; converting the alternating current produced bythe alternator into pulses of direct current, wherein the electricalcharacteristics, including amperage, voltage, phase difference betweencurrent and voltage and frequency of the alternating electric currentare regulated, the regulation occurring in response to controlling thespeed of rotation of the rotary assembly by resisting torque imposed bythe alternator by modulating the pulses of continuous current producedby the conversion means of the power electronics module resulting fromthe alternating electric current produced by the alternator, wherein themaximum speed of rotation of the rotary assembly of the wind machine isregulated at a value permitting disengagement of the blades of therotating part of the wind machine for a predetermined wind speed, bymodulating the pulses of continuous current produced by said conversionmeans.